Re: Forth for education

From	"Rod Pemberton" <dont_use_email@nohavenotit.com>
Newsgroups	comp.lang.forth
Subject	Re: Forth for education
Date	2013-09-18 21:10 -0400
Organization	Aioe.org NNTP Server
Message-ID	<op.w3mv77yw0e5s1z@localhost> (permalink)
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On Wed, 18 Sep 2013 17:08:00 -0400, Gerry Jackson  
<gerry@jackson9000.fsnet.co.uk> wrote:

> On 18/09/2013 14:41, Rod Pemberton wrote:
>> On Wed, 18 Sep 2013 03:57:19 -0400, Andrew Haley
>> <andrew29@littlepinkcloud.invalid> wrote:

>> Don't you think four decades of conversation on what's the best
>> way to implement control-flow in Forth is enough?  When it's not how
>> to implement control-flow, it's how to use DOES> ...  Etc., Forth is
>> cryptic, Forth has no syntax.
>
> Nonsense. Of course Forth has some syntax, [...]

Forth has no official syntax.  It has some defacto syntax.

E.g., brackets [ ] to distinguish compile-time and run-time
versions of the same Forth word.  : (colon) and ; (semis)
could also be viewed as syntax since they separate much
of an immediate stream of executing words from words that
are being compiled.  Etc.

> [...] if there were no syntax how could a Forth interpreter make any  
> sense of a Forth program.

Each Forth word has an action or many.  The entire action is independent
of other words, although correct execution may depend on data provided
by other Forth words or on the stacks, etc.

> According to Wikipedia:
>
> <quote>Computer language syntax is generally distinguished into three  
> levels:
>      Words – the lexical level, determining how characters form tokens;
>      Phrases – the grammar level, narrowly speaking, determining how
>                tokens form phrases;
>      Context – determining what objects or variables names refer to, if
>                types are valid, etc.</quote>
>
...

> At the lexical level Forth clearly has a simple syntax, "a parsed  
> sequence of non-space characters ..."

I.e., no official syntax, except a space.  E.g., I could throw out
all standard names, use binary and hex, and it'd still be Forth,
as long as I used spaces.

> At the grammar level control structures such as IF ... ELSE ...
> THEN clearly form part of Forth's syntax -

Not so.

> if there is no terminating THEN, the structure is wrong.

Really? Says who or what?

Which standard or document do you think requires that?

Hint:

fig-Forth doesn't say that.
F-79 doesn't say that.
F-83 doesn't say that.
ANS doesn't say that either.

fig-Forth comes the closest, saying that THEN an alias for ENDIF is
"only" supposed to be used with IF.  ANS is the least specific.

However, there is no constraint in the stack parameters for any of
them that would actually require a Forth implementor to only allow
THEN to be used with an IF or ELSE.  THEN can function correctly
as long as the stack parameters are valid.  E.g., I could define
the "WADADABOOP" control-flow to work correctly with and be
terminated by THEN.  If someone implements THEN to require a matching
IF , they've added additional functionality not required, perhaps
for safety.  I.e., if so, then they've created syntax, but it's not
officially required.

> If all control structures, colon definitions, variable definitions
> etc are considered there is quite a bit of syntax.

Of course, that's not official syntax, but, yes, that is a trivial
amount of defacto syntax.

> The conclusion is that Forth has a *lot* of syntax and so the
> statement "Forth has no syntax" is a load of bollocks.

I think you're confusing and conflating much.

Rod Pemberton

Thread

Forth for education visualforth@rocketmail.com - 2013-09-09 05:16 -0700
  Re: Forth for education Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2013-09-09 14:59 +0200
  Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-10 04:30 -0400
    Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-10 08:00 -1000
      Re: Forth for education hughaguilar96@yahoo.com - 2013-09-10 21:32 -0700
        Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-11 06:22 -0400
          Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-11 11:52 +0100
            Re: Forth for education Matthias Koch <matthias.koch@hot.uni-hannover.de> - 2013-09-11 14:40 +0200
            Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-12 08:10 -0400
              Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-12 14:20 +0100
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-14 22:47 -0400
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-14 17:47 -1000
                Re: Forth for education stephenXXX@mpeforth.com (Stephen Pelc) - 2013-09-15 17:17 +0000
                Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-15 18:52 +0100
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-15 08:11 -1000
                Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-15 19:49 +0100
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-15 09:11 -1000
                Re: Forth for education hughaguilar96@yahoo.com - 2013-09-15 20:38 -0700
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-17 17:21 -0400
                Re: Forth for education Spam@ControlQ.com - 2013-09-17 18:01 -0400
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-17 14:31 -1000
                Re: Forth for education hughaguilar96@yahoo.com - 2013-09-17 22:20 -0700
                Re: Forth for education hughaguilar96@yahoo.com - 2013-09-17 22:23 -0700
                Re: Forth for education Bernd Paysan <bernd.paysan@gmx.de> - 2013-09-18 21:56 +0200
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-18 02:57 -0500
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-18 09:41 -0400
                Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-18 15:35 +0100
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-18 21:02 -0400
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-18 15:42 -1000
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 15:48 -0400
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-20 11:26 -1000
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 20:35 -0400
                Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-19 13:45 +0100
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 16:18 -0400
                Re: Forth for education Alex McDonald <blog@rivadpm.com> - 2013-09-20 14:06 -0700
                Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-20 17:08 -0400
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-20 12:00 -1000
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 20:10 -0400
                Re: Forth for education hughaguilar96@yahoo.com - 2013-09-20 23:23 -0700
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-21 13:09 -0400
                Re: Forth for education Mark Wills <markrobertwills@yahoo.co.uk> - 2013-09-23 01:55 -0700
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-23 11:40 -0500
                Re: Forth for education albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-09-23 17:45 +0000
                Re: Forth for education anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-09-23 18:47 +0000
                Re: Forth for education albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-09-24 17:00 +0000
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-23 14:51 -0500
                Re: Forth for education albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-09-24 16:50 +0000
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-24 12:02 -0500
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-21 05:21 -0500
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-21 14:15 -0400
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-21 08:52 -1000
                Re: Forth for education Paul Rubin <no.email@nospam.invalid> - 2013-09-21 14:23 -0700
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-22 04:53 -0500
                Re: Forth for education hughaguilar96@yahoo.com - 2013-09-22 19:00 -0700
                Re: Forth for education Whammo <sidciavic@gmail.com> - 2013-09-22 21:22 -0700
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-23 08:13 -1000
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-25 04:25 -0400
                Re: Forth for education visualforth@rocketmail.com - 2013-09-24 21:38 -0700
                Re: Forth for education Rob Sciuk <rob@controlq.com> - 2013-09-23 12:07 -0400
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-23 11:50 -0500
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-25 03:58 -0400
                Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-26 09:32 -0400
                Re: Forth for education hughaguilar96@yahoo.com - 2013-09-27 19:35 -0700
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-28 01:08 -0400
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-28 01:09 -0400
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-25 03:21 -0400
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-25 04:00 -0500
                Re: Forth for education Brad Eckert <hwfwguy@gmail.com> - 2013-09-25 09:26 -0700
                Re: Forth for education visualforth@rocketmail.com - 2013-09-25 15:14 -0700
                Re: Forth for education Doug Hoffman <glidedog@gmail.com> - 2013-09-26 07:51 -0400
                Re: Forth for education visualforth@rocketmail.com - 2013-09-26 23:36 -0700
                Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-21 14:40 -0400
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-21 04:46 -0500
                Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-18 11:41 -0500
                Re: Forth for education Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-09-18 22:08 +0100
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-18 21:10 -0400
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-18 16:20 -1000
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 16:39 -0400
                Re: Forth for education Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-09-19 12:47 +0100
                Re: Forth for education Spam@ControlQ.com - 2013-09-19 11:30 -0400
                Re: Forth for education Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-09-19 16:48 +0100
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 16:51 -0400
                Re: Forth for education Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-09-20 23:17 +0100
                Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-21 15:19 -0400
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-25 03:31 -0400
                Re: Forth for education hughaguilar96@yahoo.com - 2013-09-18 21:12 -0700
                Re: Forth for education Mark Wills <markrobertwills@yahoo.co.uk> - 2013-09-19 01:02 -0700
                Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-21 15:26 -0400
                Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 17:09 -0400
                Re: Forth for education anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-09-19 11:28 +0000
                Re: Forth for education Paul Rubin <no.email@nospam.invalid> - 2013-09-18 18:30 -0700
                Re: Forth for education "WJ" <w_a_x_man@yahoo.com> - 2013-09-19 22:51 +0000
                Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-15 14:06 -0400
                Re: Forth for education Brad Eckert <hwfwguy@gmail.com> - 2013-09-15 19:56 -0700
              Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-12 08:03 -1000
          Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-11 08:59 -1000
            Re: Forth for education albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-09-12 10:48 +0000
              Re: Forth for education Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-12 08:17 -0500
        Re: Forth for education "WJ" <w_a_x_man@yahoo.com> - 2013-09-13 12:48 +0000
          Re: Forth for education Mark Wills <markrobertwills@yahoo.co.uk> - 2013-09-13 06:33 -0700
          Re: Forth for education m.a.m.hendrix@tue.nl - 2013-09-13 07:25 -0700
          Re: Forth for education visualforth@rocketmail.com - 2013-09-13 21:20 -0700
          Re: Forth for education "WJ" <w_a_x_man@yahoo.com> - 2013-09-15 09:04 +0000
            Re: Forth for education mhx@iae.nl - 2013-09-15 02:57 -0700
        Forth is not interactive "WJ" <w_a_x_man@yahoo.com> - 2013-09-20 03:32 +0000
          Re: Forth is not interactive rickman <gnuarm@gmail.com> - 2013-09-20 01:20 -0400
          Re: Forth is not interactive Whammo <sidciavic@gmail.com> - 2013-09-19 23:41 -0700
            Re: Forth is not interactive "Elizabeth D. Rather" <erather@forth.com> - 2013-09-19 21:45 -1000
              Re: Forth is not interactive "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 04:09 -0400
                Re: Forth is not interactive "Elizabeth D. Rather" <erather@forth.com> - 2013-09-19 22:21 -1000
                WJ, aka William James [was Re: Forth is not interactive] "Alex McDonald" <blog@rivadpm.com> - 2013-09-20 10:55 +0100
                Re: WJ, aka William James [was Re: Forth is not interactive] Mark Wills <markrobertwills@yahoo.co.uk> - 2013-09-20 06:17 -0700
                Re: WJ, aka William James [was Re: Forth is not interactive] rickman <gnuarm@gmail.com> - 2013-09-20 13:19 -0400
                Re: WJ, aka William James [was Re: Forth is not interactive] "Alex McDonald" <blog@rivadpm.com> - 2013-09-20 19:45 +0100
                Re: WJ, aka William James [was Re: Forth is not interactive] rickman <gnuarm@gmail.com> - 2013-09-20 14:53 -0400
              Re: Forth is not interactive Mark Wills <markrobertwills@yahoo.co.uk> - 2013-09-20 01:20 -0700
          Re: Forth is not interactive Howerd <howerdo@yahoo.co.uk> - 2013-09-20 02:35 -0700
            Re: Forth is not interactive Howerd <howerdo@yahoo.co.uk> - 2013-09-20 02:39 -0700
          Re: Forth is not interactive mhx@iae.nl - 2013-09-21 04:05 -0700
          Re: Forth is not interactive albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-09-21 12:43 +0000
    Re: Forth for education stephenXXX@mpeforth.com (Stephen Pelc) - 2013-09-12 14:04 +0000
    Re: Forth for education "Ed" <invalid@invalid.com> - 2013-09-15 18:00 +1000
  Re: Forth for education voidvolker@gmail.com - 2013-09-14 10:41 -0700
    Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-14 10:53 -1000
  Re: Forth for education "WJ" <w_a_x_man@yahoo.com> - 2013-09-19 22:33 +0000
    Re: Forth for education visualforth@rocketmail.com - 2013-09-19 17:17 -0700
      Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 17:44 -0400
        Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-20 23:58 +0100
          Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-20 19:49 -0400
            Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-21 20:33 +0100
              Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-25 03:49 -0400
                Re: Forth for education "Alex McDonald" <blog@rivadpm.com> - 2013-09-25 09:42 +0100
                Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-26 09:39 -0400
                Re: Forth for education Doug Hoffman <glidedog@gmail.com> - 2013-09-26 10:40 -0400
                Re: Forth for education "Elizabeth D. Rather" <erather@forth.com> - 2013-09-26 08:51 -1000
        Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-20 22:50 -0400
          Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-21 14:27 -0400
            Re: Forth for education rickman <gnuarm@gmail.com> - 2013-09-21 15:33 -0400
              Re: Forth for education "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-25 03:37 -0400
        Re: Forth for education Paul E Bennett <Paul_E.Bennett@topmail.co.uk> - 2013-09-21 10:02 +0100

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